RT Journal Article ID 5a52e345738e1f68 A1 Guidoin, Robert A1 Bes, Taniela Marli A1 Cianciulli, Tomas Francisco A1 Klein, Julianne A1 Li, Bin A1 Gauvin, Robert A1 Guzman, Randolph A1 Rochette-Drouin, Olivier A1 Germain, Lucie A1 Zhang, Ze T1 Cuspal Dehiscence at a Post and Along the Stent Cloth in a Bovine Pericardium Heart Valve Implanted for Seven Years JF Journal of Long-Term Effects of Medical Implants JO JLT YR 2012 FD 2013-02-12 VO 22 IS 2 SP 95 OP 111 K1 dehiscence K1 pericardium valve K1 abrasion K1 collagen remodeling AB A failing mitral valve prosthesis made from bovine pericardium was explanted from a 50-year-old patient. Preoperative transthoracic–echocardiography had confirmed severe mitral regurgitation due to structural failure of this HP Bio bovine pericardium heart valve prosthesis. The explanted device was examined macroscopically, by scanning electron microscopy (SEM), by light microscopy, and by transmission electron microscopy (TEM). Samples of unassembled patches of bovine pericardium were used as a pre-implantation control to better understand the changes that occurred in the structure of the pericardium following the 7 years of implantation. Examination confirmed complete dehiscence of a cusp along a valve post and the stent: This detached cusp was observed floating in the bloodstream at echocardiography. The fibrous pannus overgrowth was well developed along the stent and extended to the bottom of the cusps both on the inflow and the outflow sides. The fibrous panni were found to be poorly adhesive to the pericardium cusps and had become stiff, thus impairing the opening and closure of the valve. The structure of the pericardium cusps was severely deteriorated compared to the control bovine pericardium tissue samples. The collagen bundles were frequently broken and more stretched in the explanted device, lacking the wavy histological pattern of normal collagen fibers. However, the tissues were devoid of any calcification. In conclusion, the failure mode of this valve was the dehiscence of a cusp from a valve post and along the stent cloth in the absence calcification. PB Begell House LK https://www.dl.begellhouse.com/journals/1bef42082d7a0fdf,4bae91265145243a,5a52e345738e1f68.html